Resilient tooth brush with adjustable pressure point



Feb. 10, 1970 a. 5. DE BIANCHI 3,493,991

RESILIENT TOOTH BRUSH WITH ADJUSTABLE PRESSURE POINT Filed Aug. 24. 1967 fig.5 36 3 Wi /11117111); A0

United States Patent 3,493,991 RESILIENT TOOTH BRUSH WITH ADJUSTABLE PRESSURE POINT Giovanni Sassoli de Bianchi, Bologna, Italy, assignor to S.a.S. ARPAC, Bologna, Italy Filed Aug. 24, 1967, Ser. No. 663,119 Claims priority, application Italy, Sept. 16, 1966, Patent 789,243 Int. Cl. A46b /00; B08b 1/00 US. Cl. -143 8 Claims ABSTRACT OF THE DISCLOSURE In combination with a toothbrush having a handle made in two parts that are hingedly and resiliently secured to each other, means are provided for changing the maximum force that can be applied to the brush head without causing the two handle parts to move relatively to each other.

The present invention concerns improvements in or relating to toothbrushes.

The type of brush normally employed for dental hygiene purposes is substantially formed of a single rigid member which at one end is provided with bristles, while the other end serves as the handle. The user acts manually on the handle of the brush so that the bristles sweep over the teeth with an alternating movement in the appropriate direction so that the toothpaste thoroughly cleanses the dental surfaces. However, the pressure exerted by the hand of the user in performing such a function cannot be said in the majority of cases to result in the best preservation of theteeth and gums.

The brush is used with the expenditure of more or less energy depending upon the temperament and sensitivity of the user. It has been observed, however, that in certain cases repeated use of known brushes effected without necessary precautions may cause lesions which adversely affect the normal conditions of the teeth and the sockets thereof.

In order to specifically limit the degree of pressure that may be exerted through the brush, it has been found desirable to construct the handle of toothbrushes so that, when the user exceeds the yielding point of the resilient component connecting the members of the handle, the latter are reciprocally urgedto pass from the normal rectilinear position of alignment to a relatively angled position.

According to the present invention a brush for dental hygiene is provided which comprises a handle formed of two or more members constituting opposite levers and having a common connecting point as established by a fulcrum between the members themselves which are connectable together by a resilient member.

When the handle begins to bend or to form an angle, the user realizes that the limit of pressure or yeld point has been exceeded and is therefore compelled to reduce the degree of force exerted on the handle, so that the end of the brush will return to the normal rectilinear position.

The return of the handle to the straight position, ac; cording to the concept of the present invention, may be also adjusted from case to case and graduated as desired according to the personal requirements of the user so that, for any particular type of brush, the pressure which can be exerted on the teeth and gums is the most suitable from the point of dental hygiene.

The invention will be described further, by way of example, with reference to the accompanying drawings in which:

FIGURE 1 is a side view of a first embodiment of the 3,493,991 Patented Feb. 10, 1970 invention showing the hinge connection 4 between the two members 2 and 7 of the toothbrush as being positioned along the longitudinal axis of said two members;

FIGURE 2 is a partial side view of a second embodiment of the invention showing the hinge connection 10 as being positioned at the mating terminals of the notched portions of members 8 and 13 of the toothbrush;

FIGURES 3 and 4 are partial side views of a third and fourth embodiments of the invention showing the hinge connections 18 and 28, respectively, as being positioned at opposite terminals of the notched portions of members 16-19, and 24-25, respectively, of the toothbrush;

FIGURE 5 is a partial side view of a fifth embodiment of the invention, in which the members 32 and 33 of the toothbrush are operable by means of a nut-containing adjustable traction member 37; and

FIGURE 6 is a partial side view of a sixth embodiment of the invention, in which the members 39 and 40 of the toothbrush are operable by means of a controllable inner member 42.

Referring now to FIGURE 1, the handle of the brush is formed by two L-shaped members 23 and 7-6 with the sections 3 and 6 being opposite to each other. The member 2-3 comprises the bristles 1 at the end of straight section 2 and the member 7-6 forms the handle with its straight section 7. A resilient member 5 which may be a band of rubber is mounted on the sections 3 and 6 of the said members 2-3 and 7-6.

Changes in the position of the resilient member 5 relative to the apex 4 are achieved by means of notches 8 and 9, formed on the two sections 3 and 6 for retaining the resilient member 5 in a preselected position. This renders possible the variation in the force which tends to bring together the sections 3 and 6 of the two L-shaped members. As it can be readily surmised, members 2-3 and 7-6 function exactly as two opposite disposed levers at the point 4 which serves as a pivot point for both levers. The resilient member 5 acts on the notches 9 and 8 so as to resist the action of the force exerted on one member by the opposition of the teeth on the end section 2 of the member 2-3 and of the force exerted on the other side on section 7 of the member 7-6 by the hand operating the brush.

FIGURE 2 shows an arrangement similar to the one shown in FIGURE 1. In this case, the sections 9 and 11 of the top members 8-9 and 13-11 instead of being upwardly directed are downwardly directed with respect to the bristles (not shown). The hinge 10 connects the two members together at the lower end of the sections 9 and 11. In this case the resilient member 12 which may be a band of rubber is also positioned in the notches 14 and 15 on the sections 9 and 11.

The two members 8-9 and 13-11 function exactly as two levers opposite to each other at point 10, which functions as a pivot point for both levers. In this case, however, the resilient member 12 acts on the notches 14 and 15 so as to resist the action of the forces acting at both ends of sections 8 and 13 of the members 8-9 and 13-11.

In FIGURE 3 a different construction is shown of the two members forming the handle of the brush. These members 16-23 and 19-22 are provided with dove-tailed regions in their respective end sections 23 and 22. A connecting hinge 18 is inserted between the cutaway end section 23 of the member 16-23 and the middle of the plane of the member 22-19. The resilient connection between the two is obtained by means of member 17 which may be located in the corresponding notches 21 and 22 formed on the end sections 23 and 22. Again, in this case, the two members 16-23 and 19-22 act as two levers opposite to each other at the point 18 which serves for both levers as a fulcrum. The resilient member 17 which may be a band of rubber acts on the notches 21 and 20 so as to exert a force resisting the action of the forces acting on the two end sections 16 and =19.

FIGURE 4 shows another embodiment of the invention, in which the handle of the brush has the same features as those for the brush handle shown in FIGURE 3 but structurally in reversed order.

In this case, again, the two members 2426 and 25-27 function as two opposite levers with a common pivot point at the hinge 28. The resilient member 29 which may be a band of rubber exerts on the end sections 26 and 27, and more particularly on the notches 30 and 31 thereof, a force opposite to the forces applied at the two end sections 24 and 25 of the members 2426 and 25-27.

FIGURE shows another version of a brush handle in which two members 32 and 33 of the handle have projections 34 and 35 extending upwardly from the surfaces of the members 32 and 33. The projections 34 and 35 extend in the direction of the bristles (not shown). A hinge 36 is provided between these projections for connecting the ends of the two members 32 and 33 together and is positioned in the upper portion of the handle. A resilient connecting member 37 has a traction effect and the adjustment in the traction may be obtained by rotating an adjustment nut 38, the operation of which is opposed by the projection 35 and the thread of the nut engaging threading of the screw formed in the projection 35 of the member 33. In this case the two members 32 and 33 act as two opposite levers, the common fulcrum of which is positioned at the hinge 36, while the resilient member 37 exerts a force at the points 34 and 35 counteracting the force exerted at both ends of the members 32 and 33.

FIGURE 6 shows another embodiment of opposing levers in the handle of a toothbrush. The two members 39 and 40 of the handle each have an internal cavity 43-44. The cavity 43, formed in the member 39, extends only a short distance, while the internal cavity 44 extends over the complete length of the member 40 and has a screw thread 49 at one end engageable by the mating thread 48 of a nut 47.

A resilient member 42 is firmly connected to the member 39 at the end of the cavity 43 and to the member 40 by being secured to the nut 47.

The resilient member exerts a traction efiect so that, in the resting position, the two members 39 and 40 are held relatively straight with the end surfaces fitting together perpendicularly to their respective longitudinal axes. However, by applying a force at the ends 39 and 40, the resilient member 42 extends and exerts a force at the points 45 and 46, the point 41 being the fulcrum of the two opposing levers 39-45 and 40-46.

What is claimed is:

1. In a toothbrush having a brush head, a two section handle of which one section supports the brush head and hinge means securing the two handle sections to each other, the improvement comprising the combination of:

(a) support means integral with each of the two handle sections;

(b) an elongated, resilient, member having a first end portion coupled to one of said support means and a second end portion coupled to the other of said support means, said resilient member thereby applying a force on the two handle section for aligning the handle sections and inhibiting relative movement thereof when a force less than a predetermined force is exerted on the brush head by the user; and

(c) means for changing the magnitude of the force applied by said resilient member on the two handle sections whereby the two handle sections will move relative to each other when the predetermined force on the brush head is exceeded.

2. The toothbrush in accordance with claim 1 wherein said support means comprises a post extending outwardly from each handle section and said force changing means comprises a plurality of axially spaced notches on each of said posts, the end portions of said resilient member being positioned in selected ones of said notches.

3. The toothbrush in accordance with claim 2 wherein the handle sections are hingedly secured to each other proximate the juncture of respective ones of said posts and handle sections.

4. The toothbrush in accordance with claim 2 wherein the handle sections are hingedly secured to each other at the outer ends of said posts.

5. The toothbrush in accordance with claim 1 wherein said support means comprise a post extending coaxially with each of the handle sections and said force changing means comprises a plurality of axially spaced notches on each of said posts, the end portions of said resilient member being positioned in selected ones of said notches.

6. The toothbrush in accordance with claim 5 wherein the handle sections are hingedly secured to each other at the juncture of one of said posts and its respective handle section.

7. The toothbrush in accordance with claim 1 wherein said force changing means comprises a member threadably secured in one of said support means and connected to one of the end portions of said resilient member whereby rotation of said threaded member will change the force applied by said resilient member.

8. The toothbrush in accordance with claim 1 wherein at least a portion of both of the handle sections is hollow and said resilient member is disposed within the hollow portions of the handle sections, said force changing means comprising a member threadably secured to one of the handle sections and coupled to one of the end portions of said resilient member whereby the rotation of said threadably mounted member will vary the force applied to said resilient member.

References Cited DANIEL BLUM, Primary Examiner US. Cl. X.R. 15-167; 306-20 

